945 resultados para Fractions. Activities. Operations With Fractions


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With the high oil price variability, the petroleum and the reservoir engineers are usually face to face on how they can evaluate the well performance and productivity. They can improve high productivity from the well construction to the secondary recoveries, but they have never tried a measurement in the drilling operations about the lower productivity index. As a rule, frequently the drilling operations hear from the reservoir engineering and geology that, if there is a formation damage, probably some drilling operations practices were not done properly or the good practice in petroleum engineering or mud engineering were not observed. The study in this working search is an attempt of how to measure a formation damage just from the project drilling to the drilling operations, with datum from the fields in Brazilian northeast and putting into practice a Simulator developed from the modeling on the theory offered by different experts and sources in formation damage

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Estuaries are environments prone to the input of chemical pollutants of various kinds and origins, including polycyclic aromatic hydrocarbons (PAHs). Anthropogenic PAHs may have two possible sources: pyrolytic (with four or more aromatic rings and low degree of alkylation) and petrogenic (with two and three aromatic rings and high degree of alkylation). This study aimed to evaluate the levels, distribution and possible sources of polycyclic aromatic hydrocarbons in the estuary of the Potengi river, Natal, Brazil. Samples of bottom sediments were collected in the final 12 km of the estuary until its mouth to the sea, where the urbanization of the Great Natal is more concentrated. Sampling was performed on 12 cross sections, with three stations each, totaling 36 samples, identified as T1 to T36. The non alkylated and alkylated PAHs were analyzed by gas chromatography coupled to mass spectrometry (GC / MS). PAHs were detected in all 36 stations with total concentration on each varying 174-109407 ng g-1. These values are comparable to those of several estuarine regions worldwide with high anthropogenic influence, suggesting the record of diffuse contamination installed in the estuary. PAHs profiles were similar for most stations. In 32 of the 36 stations, low molecular weight PAHs (with 2 and 3 ring: naphthalene, phenanthrene and their alkylated homologues) prevailed, which ranged from 54% to 100% of the total PAH, indicating that leaks, spills and combustion fuels are the dominant source of PAH pollution in the estuary. The level of contamination by PAHs in most stations suggests that there is potential risk of occasional adverse biological effects, but in some stations adverse impacts on the biota may occur frequently. The diagnostic ratios could differentiate sources of PAHs in sediments of the estuary, which were divided into three groups: petrogenic, pyrolytic and mixing of sources. The urban concentration of the Great Natal and the various industrial activities associated with it can be blamed as potential sources of PAHs in bottom sediments of the estuary studied. The data presented highlight the need to control the causes of existing pollution in the estuary

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This proposal is to search, investigate practical experience in environmental education for the construction of Local Agenda 21, in the municipality of Maxaranguape-RN, attended that brought together various subject and collective social actors of civil society organizations, among them, the Center for Education and Advice Herbert de Souza - CEAHS (NGOs who serves on the council since 1999), associations of farmers and farmers in areas of settlements, teachers / as, groups of women and young people, entrepreneurs, public power, the German partner entities IBAMA. INCRA, BNB in the project of Agenda 21. They are members and participants, constituents of the Permanent Forum of Agenda 21, the main actor privileged in the search. As an object of study to identify the limits and scope of this practice, with regard to aspects of awareness / participation and awaken to an awareness of critical social subjects in the collective social and environmental perspective. The study seeks to investigate if this experience has allowed the individual and collective social subjects, understand and act in their daily life, as the changes in attitudes postures, and expand their interests to participate in various public spaces this intention, is considered the educational activities made with the principles of environmental education in the construction of Agenda 21 that have contributed in raising awareness / participation of social actors of the Permanent Forum of Agenda 21. While reference methodology, the research focuses on theoretical design Freireana with relevance on the dimensions of dialogue, critical thinking and the human dimension comprising the act as educational practice of freedom, the prospect of human emancipation and social transformation of reality, and bring other thinkers as, Carvalho (2004), Trigueiro (2003), Days (2004), among others. The investigation of this practice points to the subject of education, which ECOCIENCIA to install the Agenda 21 and its effect on demand under municipal, German, providing a change of attitudes and postures and certainly, generating a new look and act in the world, broadening their interests and desires of inserting themselves, to participate in public spheres, particularly in establishing relations with dialogical criticality with the authorities and face the demands socio-environmental locations.

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Este trabalho foi realizado para avaliar o efeito da adição de enzima e/ou probiótico, bem como do estresse calórico sobre a atividade de enzimas digestivas de frangos de corte aos 7, 14, 28 e 42 dias de idade. O delineamento experimental utilizado foi o inteiramente casualizado em parcelas subdivididas com 6 tratamentos primários, constituindo um esquema fatorial 6x2 (rações x temperatura) e 4 tratamentos secundários (idades de amostragem), com 2 repetições. Não foi verificado efeito significativo dos tratamentos sobre a atividade específica das enzimas, exceto para as atividades de amilase aos 14 dias e tripsina aos 28 dias de idade, nas quais a adição de enzima proporcionou maiores atividades. Já a idade de criação afetou significativamente todas as enzimas quantificadas, sendo que a atividade específica de lipase diminuiu e as atividades específicas de amilase, tripsina e quimotripsina aumentaram com a idade das aves. A temperatura ambiente (calor) também afetou a produção enzimática de acordo com a idade dos frangos de corte, com um aumento na atividade de lipase e redução na tripsina e amilase.

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The aim of the present work is to contribute to the teaching-learning process in Mathematics through an alternative which tries to motivate the student so that he/she will learn the basic concepts of Complex Numbers and realize that they are not pointless. Therefore, this work s general objective is to construct a didactic sequence which contains structured activities that intends to build up, in each student s thought, the concept of Complex Numbers. The didactic sequence is initially based on a review of the main historical aspects which begot the construction of those numbers. Based on these aspects, and the theories of Richard Skemp, was elaborated a sequence of structured activities linked with Maths history, having the solution of quadratic equations as a main starting point. This should make learning more accessible, because this concept permeates the students previous work and, thus, they should be more familiar with it. The methodological intervention began with the application of that sequence of activities with grade students in public schools who did not yet know the concept of Complex Numbers. It was performed in three phases: a draft study, a draft study II and the final study. Each phase was applied in a different institution, where the classes were randomly divided into groups and each group would discuss and write down the concepts they had developed about Complex Numbers. We also use of another instrument of analysis which consisted of a recorded interview of a semi-structured type, trying to find out the ways the students thought in order to construct their own concepts, i.e. the solutions of the previous activity. Their ideas about Complex Numbers were categorized according to their similarities and then analyzed. The results of the analysis show that the concepts constructed by the students were pertinent and that they complemented each other this supports the conclusion that the use of structured activities is an efficient alternative for the teaching of mathematics

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The present study aims to analyze the potentialities and limitations of GeoGebra software on what concerns trigonometry s teaching and learning processes. Taking the present resources of public school from the state of Rio Grande do Norte, the research intends to answer the following question: Could we use the current conditions of public school and the Geogebra software to optimize the trigonometry s learning and teaching processes situation? . To make it a possible to answer the question above, a module of investigative activities was created and applied. The methodological intervention was made among second year High School students from a public school in Natal, RN. The theoretical reference of Mathematics Didactics was taken was a base, adopting the conceptions of Borba and Penteado (2001), Valente (1999) and Zulatto (2002, 2007) about the use of Information Technology (IT) on Mathematics classrooms. In order to create the investigative activities helped us to understand how the students make their constructions and their visual perception through the process of dragging images on the computer screen. Furthermore, the activities done with the GeoGebra software s resources facilitate the resolution of trigonometry situations

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The present study investigates how the inter-relationship of the content of polynomial equations works with structured activities and with the history of mathematics through a sequence of activities presented in an e-book, so that the result of this research will proceed will result in a didactic and pedagogic proposal for the teaching of polynomial equations in a historical approach via the reported e-book. Therefore, we have considered in theoretical and methodological assumptions of the History of Mathematics, in structured activities and new technologies with an emphasis on e-book tool. We used as a methodological approach the qualitative research, as our research object adjusts to the objectives of this research mode. As methodological instruments, we used the e-book as a synthesis tool of the sequence of activities to be evaluated, while the questionnaires, semi-structured interviews and participant observation were designed to register and analyze the evaluation made by the research, participants in the structured activities. The processing and analysis of data collected though the questionnaires were organized, classified and quantified in summary tables to facilitate visualization, interpretation, understanding, and analysis of these data. As for participant observation was used to contribute to the qualitative analysis of the quantified data. The interviews were synthetically transcribed and qualitatively analyzed. The analysis ratified our research objectives and contributed to improve, approve and indicate the use of e-book for the teaching of polynomial equations. Thus, we consider that this educational product will bring significant contributions to the teaching of mathematical content, in Basic Education

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n this work, we analyze the behavior of the chromospheric and coronal activities as a function of the mass and the orbital period of extrasolar planets which were detected by transit technique. So we look for possible effects of the planet on the star s chromosphere and corona. For this study we selected a sample of 48 stars with chromospheric activity indicator and 23 with coronal activity indicator. Our work is based on the work from Pont et al. (2011) in order to study stars with planets which were obtained by transit technique. Furthermore, we studied the relationship between planetary mass and orbital period with the chromospheric and coronal activity in order to better understand which influences the planets cause in the outer layers of stellar atmosphere. In our analysis we can observe that the mass of the planets exerts no influence in the stellar activity. However, we observed that the stellar coronal and chromospheric activities decrease with the increase of the orbital period of the planet

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In this work, we analyze the behavior of the chromospheric and coronal activities as a function of the mass and the orbital period of extrasolar planets which were detected by transit technique. So we look for possible effects of the planet on the star s chromosphere and corona. For this study we selected a sample of 48 stars with chromospheric activity indicator and 23 with coronal activity indicator. Our work is based on the work from Pont et al. (2011) in order to study stars with planets which were obtained by transit technique. Furthermore, we studied the relationship between planetary mass and orbital period with the chromospheric and coronal activity in order to better understand which influences the planets cause in the outer layers of stellar atmosphere. In our analysis we can observe that the mass of the planets exerts no influence in the stellar activity. However, we observed that the stellar coronal and chromospheric activities decrease with the increase of the orbital period of the planet

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Activity profiles of excess Pb-210 combined with chemical data determined in two sediment cores from Corumbatai River basin, São Paulo State, Brazil, provided new insights into the reconstruction of historical inputs of anthropogenic constituents, contributing to improving management strategies of the hydrological resources in the basin since most of the municipalities extensively utilize the waters of Corumbatai River and tributaries for drinking purposes, among other uses. Excellent significant relationships between loss on ignition (LOI) and organic matter were found for sediments of both analyzed profiles. Silica was found to be inversely related to organic matter at both analyzed profiles: its decrease accompanied an increase in the specific surface of the sediments. This relationship was confirmed by a great number of inverse significant correlations among silica and oxides Na2O, K2O, CaO, MgO, Al2O3, P2O5, Fe2O3, MnO, and TiO2. It was possible to identify the role of organic matter on adsorption of several oxides/elements in the core sediments profiles. Apparent sediment mass accumulation rates corresponding to 224 and 802 mg cm(-2) year(-1) were obtained, and are compatible with field evidence, indicating a higher value associated with sand mining activities interfering with the natural/normal sedimentation process, due to modifications of the channel drainage.

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This work presents an experimental study on the life of abrasive discs in cut-off type operations with two conditions of cutting speed. The cutting time is shown with a comparative analysis of the cutting speed.

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Includes bibliography

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Includes bibliography

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Includes bibliography